It’s starting to look like the litigation surrounding DePuy Orthopaedic’s recalled ASR Hip Replacement Systems could turn out to be one of the biggest legal stories of the year. According to The Wall Street Journal, roughly 1,000 personal injury lawsuits involving the DePuy ASR hip implants are pending in federal courts around the country, and more are expected.

The DePuy ASR Hip Resurfacing System was recalled last year, along with the DePuy ASR Acetabular System, after data from the National Joint Registry of England and Wales showed that 1 out of every 8 patients (12%-13%) who had received the devices had to undergo revision surgery within five years of receiving. The DePuy ASR Hip Resurfacing System was used in the U.K., but was not approved by for sale in the U.S. The ASR Acetabular System was approved for sale here, and it was widely used in the U.S. According to The Wall Street Journal, many plaintiffs in DePuy ASR hip implant lawsuits claim they had to undergo risky and expensive surgery to remove and replace the recalled implant.

As we’ve reported previously, the DePuy ASR Hip Resurfacing System and DePuy ASR Acetabular System are all-metal hip implants, a class of devices that have been the subject of safety concerns for several years now. Many plaintiffs in these lawsuits have high chromium and cobalt in their bloodstreams and allege the potentially toxic metals came from parts of the joint wearing down and leaching into their system, the Journal said. There are concerns that high concentrations of metal debris in the blood stream might cause tissue loss, bone damage, the formation of non-cancerous tumors and other long-term health problems. Last month, the U.S. Food & Drug Administration (FDA) asked DePuy Orthopaedics and 20 other manufacturers of metal-on-metal hip implants to conduct safety studies aimed at determining if these devices are shedding dangerous amounts of metallic debris in patients.

DePuy ASR Hip Implant lawsuits also claim that the company, a division of Johnson & Johnson, knew about the problems associated with the devices years before they were recalled. They point out that an Australian device regulator warned DePuy about high rates of failure and complications from the ASR devices in 2007. According to the Journal, the regulator also took steps to curb the use of the devices there, resulting in a marked reduction in their use in Australia.

DePuy, which stopped making the ASR hip implants in 2009, denies these allegations, despite finally issuing the worldwide recall in 2010. However, its parent company, Johnson & Johnson, boosted its reserves for legal costs related to its products, including the recalled hip joints, by $570 million last year, the Journal said. It also set aside $280 million to cover surgeries and other medical care for patients with the recalled hip implants.

As we’ve reported previously, many DePuy ASR hip implant lawsuits have been consolidated in a multidistrict litigation in U.S. District Court for the Northern District of Ohio. According to the Journal, some plaintiffs’ lawyers want the lawsuits certified as a single class action complaint.